Die Bodenkultur - Journal for Land Management, Food and Environment

The effect of keeping fattening pigs in groups on fully slatted floor and in danish boxes with straw litter at different environmental temperatures on growth rate, food conversion and carcass quality

Summary

Within seven replications 220 fattening pigs were kept in two separated rooms prepared far different thermal conditions, one of them heated to about 20 °C at the beginning with the temperature gradually declining to 15 °C: the other one not heated during the winter replications with temperatures of about 12 to 15 °C at the beginning, then declining to 8 to 13 °C within a few weeks with naturally fluctuating circadian sinusoidal variations, minimal temperatures going down sometimes to 3 °C. In each room two different boxes for eight pigs were installed. One box had a fully slatted floor, the other one being a type of danish box with resting area being littered by chopped straw (0.2 kg/pig and day). The animals were fed restrictively, metabolizable energy supply was 1.47 MJ/kg W" at 25 kg lifeweight gradually declining to 1,13 MJ/kg W" at 100 kg (W" = metabolical weight= kgO.75) . The food supply of the pigs in the cold housed group with straw was 11 % (0.2 kg/day) less than that of the other animals due to a malfunction of the feeding station not detected by the control pe and not perceived on time.

Daily gain of the warm housed pigs with straw litter was 45 g higher compared with the animals on slatted floor at same temperatures. In the cold room this difference was even 97 g. The mean superiority of the littered boxes over the year was 72 g. With 11 % less food intake, the cold housed pigs with straw showed some daily gain, same length of fattening period and slightly better food conversion than warm housed animals on slatted floor. Straw has various beneficial effects not only thermal ones.

There were no differences between the groups at most of the criteria of carcass quality except the percentage of loin area, which was significantly smaller in the pigs housed cold on slatter floor. Alls pigs on slatted floors had significantly shorter body lengths than those with straw probably caused by unnormal lying behaviour on the belly. Pigs on slatted floors showed a significant higher frequency of technopathies, especially alterations of joints (lamness) and injuries of the integument.

Better growth rates of animals kept with straw, the possibility to avoid heating costs and new housing systems which need very small amounts of straw, e. g. "straw-flow-systems" or systems with closed nest boxes, give the possibility to combine welfare aspects of the pigs with economic improvement of production.